Process for hydrogenating and cracking petroleum oils



Nov. 27, 1956 w. LANGER, JR

PROCESS FOR HYDROGENATING AND CRACKING PETROLEUM OILS Filed Dec. 24, 1953 on Q)? m V A IN VE N TOR Hydrogenutor HDDC 1 H dro enuted Al x85 226 :0 EEEI M o Fruciionotor ATTORNEY all United States Patent ()fi ice PROCESS FOR HYDROGENATING CRACK- ING PETROLEUM OILS,

Arthur W. Langer, Jr., Nixon, N. J.,' assignor to Essa Research and Engineering Company, 'a' corporauon of Delaware Application December 2 4, 1953, Serial No. 400,231- 2 Claims. c1. 196-49) forms a part of this invention, no elaborate presentation of the technique of catalytic cracking will be made in describing this invention for the above reason.

Recently a process termed hydrogen donor diluent cracking (HDDC) has been proposed. In this process an oil is upgraded by admixing it with a hydrogen donor diluent material, aromatic in nature, and cracking the mixture either thermally or catalytically. The donor diluent is a material such as a thermal tar boiling in the range of 700 to 900 F. having the ability to take up hydrogen in a hydrogenation zone and readily release it in the thermal cracking zone. The donor material is partially hydrogenated by conventional methods using, preferably, a sulphur insensitive catalyst like molybenum sulfide. In this manner of hydrocracking of oils, the oil being upgraded is not contacted directlywith the cata-. lyst and does not, therefore, impair its activity by contamination. The amount of concomitant light gases and coke produced by this process is extremely small, usually being about to 10%. more fully presented by co-pending application, entitled, Upgrading of Heavy Hydrocarbon Oils, by Langer, et;al., S.'N. 365,335, filed on July 1, 1953.

Co-pending application entitled, Conversion ofResidual Oil Fractions by Langer et al., S. N. 365,338, filed on July 1, 1953, points out that a partially hydrogenated,

hydrogen donordiluent can be effectively used in a hydrocracking process to produce good yield of motor fuel or gasoline of. a relatively high octane number from heavy residual stocks. It discloses that by adding 5 to 200% by volume of a partially hydrogenated diluentmaterial to a residual oil feed and passing the mixture over a dehydrogenating or hydroforming catalyst, for example, molybdenum oxide on silica-alumina, the feed can be upgraded even if highly aromatic in nature.

This invention, by the novel application of the above methods of thermal or catalytic hydrogen donor diluent cracking to the material boiling above the gasoline range from a conventional catalytic cracking process, presents a method of catalytically upgrading hydrocarbon oils that is more efiicient than those previously suggested.

Accordingly, a major object of the present invention is to convert hydrocarbon oils boiling above 400 F. to lighter, more valuable hydrocarbons such as gasoline. A further object is to catalytically treat oils, such as gas oils or heating oils and to upgrade them to motor fuels with substantially no production of residual fuels or waste materials. Further objects and advantages will appear more fully as the attached drawing, depicting schemati- The technique of HDDC is.

v 2. I I eally a preferred embodiment of the invention and torrning a part'of this specification, is discussed in detail.

Generally, the objects of this invention are attained by catalytically cracking a hydrocarbon feed in a con"- ventional manner, separating the productgases to obtain light gases, naphthas, a plurality of gas oil fractions,

cycle stock and a bottoms slurry, partially hydrogenating' a portion of a heavy fraction (hereinafter referred to as diluent) cracking the cycle stock admixed with'the par tially hydrogenated diluent and returning the cracked' mixture to the same product recovery system used by'th'e,

catalytic unit. In this manner, the cycle stock is'cr acked to extinction in the HDDC unit; As before mentioned, the HDDC unit can operate either thermally or catalytically. Alternately, the bottoms slurry from the recovery system (or the clarifier oil therefrom) can be admixed with the cycle stock for the HDDC treatment.

It is readily apparent that this invention offers the following advantages for the upgrading of hydrocarbons over the separate use of either catalytic cracking or 1. The hydrogen donor diluent'is used only for the' 3. Because the hydrogen content of catalytic ally.

cracked cycle stock is lower than that of conventional feed to the cracking process, the cycle stock is cracked most advantageously by HDDC.

4. By using the same product recovery system for bothunits, greater economies are obtained. 5. Very little low value residual material is produced because the heavy ends are treated essentially to extinc tion.

Referring now to the accompanying drawing, the feed,

such as a virgin gas oil boiling from 550 to 1050 F enters the process through line 1 and is admixed with the recovered catalyst slurry, supplied by line 2. The mix ture is passed to a catalytic cracking unit 3, here assumed to be a conventional fiuid unit with .a' catalyst regenera- I tion system. Typical cracking conditions for a silica-V alumina catalyst of 0 to 200 microns at 50 to 430 F. conversion are: temperature 850950 F., superficial vapor velocity 1-3 ft./sec., catalyst to oil ratio: 10, feed rate, 1.47 w./hr./W., and pressure 10-20 p. s. i.v g. The efliuent from the catalytic unit 3 is transferred by line 4 to a separation system, here shown to be a fractionator 6 and a settler or Dorr thickener 14. A simpleseparation system is here shown for the purpose of illustration but a more elaborate separation could be used as desired. A s

portrayed,light gases (C4) are removed from the fractionator by line 7 and sent to other processes, such as light ends'recovery unit, not shown. Thedesired naphtha or gasoline fraction (Ci-430 F.) is removed via line 8, and one or more heating oil fractions (430 to 650 F.) via line 10. Cycle stock (650800 F.) is taken off by lines 11 and llaand passed by lines 20 and 12 to the HDDC unit. The bottoms boiling above 800 F. are, passed by line 13 to the settler 14.

It is to be understood that the temperature ranges of the various fractionator streams can be varied to meet: the needs of individual processes. Clarified oil is here used as the source of the donor diluent. It contains.- higher boiling, larger condensed ring structures and will be partly cracked along with the cycle stock. The clari- Pafe nted Nov. 27, 1956 the cycleistoic k,stream Also nts: v

.Qut200.-to,6010's. or f of hydrogen per bb ly o f be passed rpm line 13; by lipe lfi and valve 116, to.

. ,.b i rr l he oil, remoyedlfrorn settler line: 1] can be sent t fiDDC nit by ealve 9,r in 0vand. 12. Ordinarily the, catalystjsusbension mim 13 iscon- 7 centrated in thesettlen 14.; The. concentrated catalyst sus'p ensw isnthenftransferried to the catalytic unit, by line ndlthe clarified. oil'is removed byline 11 the dilu enta With highvashfeed stqcks, it may benec-' yffoobleerila 'smalliamqunt of clarifieduoil through. line 29 "to prevent build upgof contaminants in tia e sys-I t, s. ,aqwxm by line; 21, withrth'e diluent. in line the mixture isnpassed ov er a hydrogenation catag in 'yessellll. Conventional operating; conditions. are such a s a temperature Qf 65f)? F., feed The conditions, in any case, should'be ritlias b en foun t mple c enation g e y. reducegs the effectiveness of a, donor-diluent, The dil uent sh'ould pick up enough, easily-removable"hydrogen tribe effectiye as a dgnor; but not enoughitoapproach saturation or to convCnitlsubstantially to 'naphthenes The unreactedhydrogen is passed overhead-byline" 23 'andgvalv'ejfl. It maybe desiredto recycle sqme of this a 'tail gasto line 21 bylines 25and Valve'26." t

r e hy o enrd nqr. d lue t s passed rQm hen hydr For thermal HDDC; a coil alone for a coilandjdrurri r t m nt m he e a u e flneafioak ab" 750;10'1000? F.'-'wit l 1 essure qfjflto 1099i fi ta jfi rj bl i ssel. 2.811 l e i it t man sl a. yd e 1 ransfer tal Su h s. actie vated'carbon', nickel sulfide; cobalt nolybdate;or molyb;

denurnoxide on silica-alumina. In the cataly tieI-ID C operation reaction 'conditions are (a)"ten 1perature; 7d(l tof1000- F:," (b) feed rate of0. 1"to 1 5VAL/hi; and;

t on;- wulslihemad hu -Li t not manda p J A A pori n or all=of thes1u 1l.

am las t ie rflzis treatment he nrq net; rom he H12 1 unit is transferred by line -5 to the fractionating column 6. The following Table I lists the preferred operating conditions for the process of this invention and presents a material balance.

7 Table l Fluid catalytic unit: t a

o Catalyst. ..silica alumina;

Temperature u n an .9002 H." Presjsure. l6,p.;s. i. g.t Oil'inlet temp era re 8003Fif Feed rate 2.4 w./hr./w... I '3 J V V Qatalyst/oil ratio 12.5.'

Hydrogenatingunitr r Catalyst A ills) 'nicli el tungsten sulfide; Temperature 650 F. Pressure 500 p. s. i. g. Throughputnnn I 0.2 5 v./v./hr. HDBG unit (non-catalytic, coiland-drum): 7'

Temperature 900'? F; .Pressure 10001p. s; i. g;

Throughputa 2jv /v./hr.

v I 7 V. V transferred to a hydrogenator 22 by line 30'to serveas to12.0 'w./hr'./w. ,and a pressure of lOQJo,

10001); S. i. g. Y -s9 chosejri thatthe diluent isionly p artially hydrogenated tarting material (Virgin West Texas oil1550?-10509 E: 23.81

It isto be understood that this" invention;is' capable of in' any modifications and is not toxbe' limitedby'tlieg V foregqing' exarnple but only by the'followingclaims: f

What is claimed is:

1; A-lrydrocarbon oil'- con'version proce'ss Whiclrcom prises catalyticallyicracking a-virgin gas oil', separating tli'e cra cked product' in a' separation; zone-to obtain 'prod Qcarbons and material boiling above 400 F partially gliydrogenatingaiportion ofsaidjmateriail boiling; above 400 R, recombining the hydrogenated portion with another portion of said material" boilingabove -400 9% F.-, converting the recombined mixture inliquid phase unden'hydrogen donor diluent cracking conditions in -the absence of a;cataly-st, and returning theconverted -mix= 'ture to:said-separation zone. a j V 2; The process of clainr 1- wherein-said cracked prod not is separated-t0 obtaina 650 to 800 =E"fraction,' and; a clarified oil boiling aha/c 800 R; saidi clarified oil- References Citedginltliezfileof:patent; 7 7

UNITED STATBSPATENTS" 

1. A HYDROCARBON OIL CONVERSION PROCESS WHICH COMPRISES CATALYTICALLY CRACKING A VIRGIN GAS OIL, SEPARATING THE CRACKED PRODUCT IN A SEPARATION ZONE TO OBTAIN PRODUCT HYDROCARBONS AND MATERIAL BOILING ABOVE 400* F., PARTIALLY HYDROGANATING A PORTION OF SAID MATERIAL BOILING ABOVE 400* F., RECOMBINING THE HYDROGENATED PORTION WITH ANOTHER PORTION OF SAID MATERIAL BOILING ABOVE 400* F., CONVERTING THE RECOMBINED MIXTURE IN LIQUID PHASE UNDER HYDROGEN DONOR DILUENT CRACKING CONDITIONS IN THE ABSENCE OF A CATALYST, AND RETURNING THE CONVERTED MIXTURE TO SAID SEPARATION ZONE. 